html{
    width: 100%;
    height: 100%;
    font-size: 13.666666vw;
    -webkit-text-size-adjust: 100%;
    -moz-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
    text-size-adjust: 100%;
    font-size: 12px;

}
body{
    width: 100%;
    height: 100%;
    font-size: 12px;
}

@media screen and (min-width:320px) and (max-width:375px){
    body{
        font-size: 12px;
    }
}
@media screen and (min-width:376px) and (max-width:414px){
    body{
        font-size: 20px;
    }
}
@media screen and (min-width:415px) and (max-width:768px){
    body{
        font-size: 25px;
    }
}